Board Thread:General Discussion/@comment-26887589-20170926040347/@comment-32781661-20171005174557

They're are more like clones of each other just that zastune was an failed/evil version that came off miku (not in anyway mirrored like rin and len tough...) she probably was made due to a bug like how len was made or something....but cousins are a good possibility but to me clones make more sense...